CN102647107A - Large-stroke micro-nano-scale linear actuator based on the principle of parasitic motion - Google Patents

Abstract

The invention relates to a big stroke micro nanoscale linear actuator based on the parasitic motion principle, which can be used for realizing big stroke micro nanoscale high-precision linear positioning in the areas of precise and ultra-precise processing, micro gripping operations and scanning and imaging. The big stroke micro nanoscale linear actuator mainly comprises a forward driving unit, a rotor unit and a backward driving unit. The forward driving unit and the backward driving unit are symmetrically installed on a pedestal and the rotor unit is installed in a groove on the pedestal. The foliated structures at two sides of the rotor of the rotor unit are connected with the output ends of the forward driving unit and the backward driving unit through clearance fit. The actuator is compact in structure and convenient and fast to control. Based on the parasitic motion principle, the big stroke micro nanoscale linear actuator can realize the millimeter-sized big stroke and micro nanoscale high-precision linear positioning function. The big stroke micro nanoscale linear actuator has a good application prospect in the areas of precise and ultra-precise processing, micro gripping operations and scanning and imaging which require big strokes and high-precision positioning.

Description

Large-stroke micro-nano-scale linear actuator based on the principle of parasitic motion

the

technical field

The present invention relates to a large-stroke micro-nano linear actuator based on the principle of parasitic motion, which can be used in precision and ultra-precision machining, micro-clamping operations, scanning imaging and other fields to achieve large-stroke micro-nano high-precision linear positioning.

Background technique

Micro-nano-level positioning devices have a wide range of application value and demand in the scientific and industrial circles. As a typical type of micro-nano positioning device, piezoelectric actuator is playing an increasingly important role in the fields of precision and ultra-precision machining, atomic force microscope, scanning electron microscope, micro-nano mechanical testing, and micro-clamping. At present, using piezoelectric drive elements based on different driving principles, researchers have developed drives with different shapes and functions. Sliding drives, etc. The piezoelectric stack direct-drive driver has the advantages of simple structure, fast response, and high resolution. However, due to the limitation of the output displacement stroke of the piezoelectric stack, the output displacement of this type of driver is very limited. The flexible mechanism driver can easily realize multi-degree-of-freedom movement, but the structure and control are complicated, and the stroke is small and the stiffness is low. The inchworm driver has the advantages of large stroke and fast response, but its structure and control are complicated, and it requires extremely high processing and assembly. Inertial drives often have a simple structure and can achieve large travel and fast response, but their low load-carrying capacity limits their use. Stick-slip actuators have a theoretically infinite stroke, but their movement speed is limited and their carrying capacity is low. To sum up, it is still a difficult point to develop a driver with large stroke, high precision, high speed and high load capacity.

Contents of the invention

The object of the present invention is to provide a large-stroke micro-nano linear actuator based on the principle of parasitic motion, which solves the above-mentioned problems in the prior art. The present invention designs a large-stroke micro-nano linear actuator based on the principle of parasitic motion, and provides an available solution for realizing large-stroke and high-precision positioning. Based on the principle of parasitic motion, this type of driver can achieve millimeter-level large strokes and micro-nano-level high-precision positioning. With the help of the driving principle provided by the present invention, it is possible to design various forms of large-stroke high-precision piezoelectric actuators to meet the different needs of precision and ultra-precision machining, micro-clamping operations, scanning imaging and other fields.

Above-mentioned purpose of the present invention is achieved through the following technical solutions:

A large-stroke micro-nano-scale linear actuator based on the principle of parasitic motion, including a positive drive unit, a mover unit and a negative drive unit. The positive drive unit, mover unit and negative drive unit are connected to the base by screws 1 connection.

The forward driving unit is composed of a forward moving piezoelectric stack 3 and a forward moving flexible hinge 4, the forward moving flexible hinge 4 is connected to the base 1 through screws, and the forward moving piezoelectric stack 3 It is installed in the groove of the forward movement flexible hinge 4 in a tight fit manner.

The negative driving unit is composed of a negative motion piezoelectric stack 7 and a negative motion flexible hinge 6, the negative motion flexible hinge 6 is connected to the base 1 through screws, and the negative motion piezoelectric stack 7 is installed in the groove of the negative movement flexible hinge 6 in a tight fit manner.

The mover unit is composed of a guide rail slider assembly 2 and a mover 5, the mover unit is connected to the base 1 through the mounting hole on the guide rail of the guide rail slider assembly 2, and the mover 5 is connected to the guide rail slider assembly 2 through screws slider connection.

The mover unit achieves clearance fit with the grooves at the output ends of the positive drive unit and the negative drive unit through the lamellar structures on both sides of the mover 5 .

The invention is based on the principle of parasitic motion, and this type of driver can realize millimeter-level large stroke and micronano-level high-precision positioning.

The beneficial effects of the present invention are: simple and compact structure, convenient control, and based on the principle of parasitic motion, it provides a large-stroke micro-nano positioning scheme for the fields of precision and ultra-precision machining, micro-clamping operation, scanning imaging, etc., using this scheme to develop The piezoelectric actuator has a theoretically infinite displacement range, and the driving speed reaches 40 microns/second at a driving voltage of 100 volts and a driving frequency of 5 Hz. Changing the driving voltage and driving frequency can easily obtain motions with different driving speeds and resolutions output. It can be used in precision and ultra-precision machining, micro-clamping operations, scanning imaging and other fields to achieve large-stroke micro-nano level high-precision linear positioning. Wide application range and strong practicability.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention, and constitute a part of the application. The schematic examples and descriptions of the present invention are used to explain the present invention, and do not constitute improper limitations to the present invention.

Fig. 1 is a three-dimensional structural schematic diagram of a large-stroke micro-nano linear actuator based on the principle of parasitic motion of the present invention;

Fig. 2 is a schematic diagram of parasitic motion generated by deformation of the elastic body of the present invention;

Fig. 3 is a schematic diagram of the present invention realizing linear drive based on the principle of parasitic motion;

Fig. 4 is the timing control diagram of the present invention based on the principle of parasitic motion to realize linear drive;

Fig. 5 is a schematic diagram of the process of realizing linear drive based on the principle of parasitic motion in the present invention;

Fig. 6 is a schematic top view of a large-stroke micro-nano linear actuator based on the principle of parasitic motion in the present invention;

Fig. 7 is a schematic front view of a large-stroke micro-nano linear actuator based on the principle of parasitic motion in the present invention;

Fig. 8 is the actual motion output curve measured under different driving voltage amplitudes of the driver of the present invention at a driving frequency of 3 Hz;

Fig. 9 is the actual motion output curves measured by the driver of the present invention when the driving voltage amplitude is 100 volts and different driving voltage frequencies.

In the figure: 1. Base; 2. Guide rail slider assembly; 3. Positive motion piezoelectric stack; 4. Positive motion flexible hinge; 5. Mover; 6. Negative motion flexible hinge; 7. Negative motion Motion piezo stack.

Detailed ways

The detailed content of the present invention and its specific implementation will be further described below in conjunction with the accompanying drawings.

Referring to Fig. 1, Fig. 6 and Fig. 7, the large-stroke micro-nano linear actuator based on the principle of parasitic motion of the present invention includes a forward drive unit, a mover unit and a negative drive unit, and the forward drive unit , the mover unit and the negative drive unit are respectively connected to the base 1 through screws.

The forward driving unit is composed of a forward moving piezoelectric stack 3 and a forward moving flexible hinge 4, the forward moving flexible hinge 4 is connected to the base 1 through screws, and the forward moving piezoelectric stack 3 It is installed in the groove of the forward movement flexible hinge 4 in a tight fit manner.

The negative driving unit is composed of a negative motion piezoelectric stack 7 and a negative motion flexible hinge 6, the negative motion flexible hinge 6 is connected to the base 1 through screws, and the negative motion piezoelectric stack 7 is installed in the groove of the negative movement flexible hinge 6 in a tight fit manner.

The mover unit is composed of a guide rail slider assembly 2 and a mover 5, the mover unit is connected to the base 1 through the mounting hole on the guide rail of the guide rail slider assembly 2, and the mover 5 is connected to the guide rail slider assembly 2 through screws slider connection.

The mover unit achieves clearance fit with the grooves at the output ends of the positive drive unit and the negative drive unit through the lamellar structures on both sides of the mover 5 .

The invention is based on the principle of parasitic motion, and this type of driver can realize millimeter-level large stroke and micronano-level high-precision positioning.

Referring to FIG. 2 , it is a schematic diagram of parasitic motion generated by deformation of an elastic body. When the elastic body A is subjected to an external load F, it will produce elastic deformation, resulting in a small movement of the output end B, including a movement Δ x along the x direction and a movement Δ y along the y direction. Utilizing the motion Δ x in the x direction, this structure has a wide range of applications in the field of micro-clamping. The movement Δx in the x direction is used to realize the clamping of the clamped object, while the movement Δy in the y direction is the additional movement caused by the deformation of the elastic body A. Because Δ y is accompanied by Δ x , the motion Δ y in the y direction is called parasitic motion. This parasitic motion is detrimental to micro-clamping applications, as it can cause sliding of the clamped object, which is detrimental to the stability of the clamping. However, the present invention utilizes this parasitic motion to realize linear drive.

See Figure 3, which is a schematic diagram of linear drive based on the principle of parasitic motion. When the deformation of the elastic body produces clamping motion Δx and parasitic motion Δy , the output end of the elastic body first produces a positive pressure N on the mover. With the increase of the parasitic motion, the mover and the output end of the elastic body have a relative movement trend. The friction force f _N is then generated. Due to the existence of parasitic motion Δ y and friction force f _N , the mover moves in a straight line along the y direction.

Referring to Fig. 4 and Fig. 5, the specific process of realizing linear drive based on the principle of parasitic motion is illustrated. As shown in Figure 5, a complete movement process mainly includes 6 steps: (a) From 0 to t1 , there is a certain gap δ between the mover and _the output end, and the clamping movement Δx is mainly used to compensate Clearance, during this period, the mover and the output end of the elastic body are not in contact; (b) at the time t ₁ , the mover and the output end of the elastic body are in initial contact; (c) at the time t ₁ to t ₂ , with the elastic body With further deformation, the clamping movement Δx and the parasitic movement Δy increase. According to Figure 3, under the action of parasitic motion Δ y and friction force f _N , the mover realizes a small linear motion along the y direction; (d) at time t ₂ , the elastic body reaches the maximum deformation, and the mover also reaches the maximum single step Displacement S ; (e) From time t ₂ to T , the elastic body gradually returns to the initial state, but its output end is still in contact with the mover, causing the mover to move in a certain negative direction along the y direction, denoted as S ₀ ; ( f) At time T , the elastic body returns to its initial state and prepares for the next motion cycle. In a motion cycle, the single-step effective motion displacement S _e is S _e = S - S ₀ . Repeat the above 6 steps to realize the continuous linear motion of the mover. Different drive speeds and displacement resolutions can be obtained by changing the drive voltage frequency and amplitude.

Referring to Fig. 6 and Fig. 7, when a driving voltage with a certain amplitude and frequency is applied to the forward piezoelectric stack 3, the forward piezoelectric stack 3 will be elongated under the action of the piezoelectric effect and transmitted through the flexible mechanism. Finally, it drives the forward motion flexible hinge 4 to generate clamping motion and parasitic motion, thereby driving the mover 5 to realize linear motion along the y direction. Through the left-right symmetrical structure design, the linear actuator can realize positive and negative movement along the y direction. A driving voltage with a certain amplitude and frequency is continuously applied to the piezoelectric stack, and the mover 5 can move continuously along the y direction with a large stroke.

Referring to FIG. 8 , it is the actual motion output curves measured by the present invention under the drive frequency of 3 Hz and different drive voltage amplitudes. Accompanying drawing 9 is the actual motion output curve measured under the present invention when the driving voltage amplitude is 100 volts and different driving voltage frequencies. When the driving voltage is 100 V and the frequency is 5 Hz, the driving speed exceeds 40 μm/s.

The above descriptions are only preferred examples of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. A large-stroke micro-nano linear actuator based on the principle of parasitic motion, characterized in that: it includes a positive drive unit, a mover unit and a negative drive unit, and the positive drive unit, the mover unit and the negative drive unit The driving unit is respectively connected with the base (1) through screws. 2. The large-stroke micro-nano linear actuator based on the principle of parasitic motion according to claim 1, characterized in that: the forward drive unit consists of a forward-moving piezoelectric stack (3) and a forward-moving flexible hinge ( 4) composition, the forward-moving flexible hinge (4) is connected to the base (1) through screws, and the forward-moving piezoelectric stack (3) is installed on the forward-moving flexible hinge (4) in a tight fit in the groove. 3. The large-stroke micro-nano linear actuator based on the principle of parasitic motion according to claim 1, characterized in that: the negative drive unit consists of a negative motion piezoelectric stack (7) and a negative motion flexible hinge (6), the negative movement flexible hinge (6) is connected to the base (1) through screws, and the negative movement piezoelectric stack (7) is installed on the negative movement flexible hinge (6) in a tight fit ) in the groove. 4. The large-stroke micro-nano linear actuator based on the principle of parasitic motion according to claim 1, characterized in that: the mover unit is composed of a guide rail slider assembly (2) and a mover (5), and the mover The unit is connected to the base (1) through the mounting hole on the guide rail of the guide rail slider assembly (2), and the mover (5) is connected to the slider of the guide rail slider assembly (2) through screws. 5. The large-stroke micro-nano-scale linear actuator based on the principle of parasitic motion according to claim 1 or 4, characterized in that: the mover unit is respectively connected to the forward direction through the sheet-like structures on both sides of the mover (5). Grooves at the output of the drive unit and the negative drive unit provide a clearance fit.

Images